I am trying to figure out if we need to use single hash function across all the places in a ssh session. i.e – signature generation/verification and HMAC calculation/validation. Is it possible to use two different hash function for signature and HMAC?
I am planning to implement SHA-256 for signature generation/verification in an embedded system. But I am concerned that if I use SHA-256 for HMAC also then there will be much impact on performance considering the lesser CPU capacity of the embedded system. I am new to cryptography so I am not much aware of these things. It will be great if anyone could help.